Correct me if I am wrong here because I honestly don't know how the old rain worked, but nothing was stolen from you IMO. The system just changed from what I see.
Under the old rain system, the pot was distributed proportionally by the user levels. In other words, someone at level 90 would receive way more than a level 40.
Right but it's not like a rakeback, it's just an extra that the site offered at the time and now they no longer do.